A mounting substrate for a liquid ejection device, such as an inkjet printhead, has conventionally been made by an insert molding process that forms both the die-attach portion for the liquid ejection device(s), including the fluid feed channels or slots with lands there-between, and a housing portion including alignment and fastening features, such as bolt holes. Such a mounting substrate is described in US Published Application No. 2008/0149024 (incorporated herein). Affixed to such a mounting substrate are one or more inkjet ejector die, an electrical lead pattern (such as a flex circuit) for providing electrical interconnection to the inkjet ejector die, and a manifold for providing fluid connection between the tight spacings of the fluid feed channels and the wider spacings of the ink tanks In addition, after electrical connection between the inkjet ejector die and the electrical lead pattern has been provided, for example by wirebonding, encapsulation is deposited over the interconnection region for mechanical and environmental protection.
Although the mounting substrate described in US Published Application No. 2008/0149024 works well, in some applications it is preferable to have fewer discrete parts. Fewer parts enables manufacturing processes that include fewer assembly steps. In addition, a configuration having fewer interfaces between discrete assembled parts can have fewer potential points of failure, thereby improving reliability during operation.
What is needed is a mounting substrate that incorporates electrical leads, protection around the interconnections to the inkjet ejector die, and optionally fluid channels to the die, as well as alignment features, provided in a simple integrated fashion.